Ning Pan,Professor,University of California

Abstract:Structuralheterogeneity and hierarchy are inherent features in biological materials, buttheir significance in affecting the system behaviors is yet to be fully understood.This article first discusses the important features characterizing a hierarchalmaterial system at various scales. It then demonstrates that such structuralmultiscale hierarchy, along with other related structural characteristics, caneffectively increasethe system specific surface area and hence the catalytic capacity, improve thematerial flexibility and resilience, and enhance synergisticallythe transport, strength and other important properties. It next deals with theassociated issues including the behavior non-affinities due to disparity in hierarchallevels and the importance of system dimensionality. Finally it also stressesthe adverse consequences once the existing structural hierarchy breaks down, especially in biologicalsystems due to various mutations. This paper examinesthese related topics with several approaches to not only reveal the underlinegeometrical and physical mechanisms, but also emphasize the ways in which suchmechanisms can be applied to developing engineered material systems with novelproperties.

March 21st 2012,10:00,1512#